CVE detail

CVE-2021-0227 — CVE-2021-0227

Published 2021-04-22 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
HIGH
severity
CVSS-derived band
7.5
CVSS v3
0–10 scale
0.0131
EPSS probability
exploitation probability, 30d
68.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

An improper restriction of operations within the bounds of a memory buffer vulnerability in Juniper Networks Junos OS J-Web on SRX Series devices allows an attacker to cause Denial of Service (DoS) by sending certain crafted HTTP packets. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. When this issue occurs, web-management, NTP daemon (ntpd) and Layer 2 Control Protocol process (L2CPD) daemons might crash. This issue affects Juniper Networks Junos OS on SRX Series: 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R3-S2; 19.2 versions prior to 19.2R1-

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: 17.3R3-S9, 17.4R2-S11, 17.4R3-S2, 18.2R3-S5, 18.3R2-S4, 18.3R3-S3, 18.4R2-S5, 18.4R3-S4, 19.1R3-S2, 19.2R1-S5, 19.2R3, 19.3R3, 19.4R2-S1, 19.4R3, 20.1R1-S2, 20.1R2, 20.2R1, and all subsequent releases.

workarounds

There are no viable workarounds for this issue. To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted administrative networks, hosts and users.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=17.3<17.3R3-S917.3R3-S9advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S11, 17.4R3-S217.4R2-S11, 17.4R3-S2advisory ↗
Juniper Networks Junos OS>=18.2<18.2R3-S518.2R3-S5advisory ↗
Juniper Networks Junos OS>=18.3<18.3R2-S4, 18.3R3-S318.3R2-S4, 18.3R3-S3advisory ↗
Juniper Networks Junos OS>=18.4<18.4R2-S5, 18.4R3-S418.4R2-S5, 18.4R3-S4advisory ↗
Juniper Networks Junos OS>=19.1<19.1R3-S219.1R3-S2advisory ↗
Juniper Networks Junos OS>=19.2<19.2R1-S5, 19.2R319.2R1-S5, 19.2R3advisory ↗
Juniper Networks Junos OS>=19.3<19.3R319.3R3advisory ↗
Juniper Networks Junos OS>=19.4<19.4R2-S1, 19.4R319.4R2-S1, 19.4R3advisory ↗
Juniper Networks Junos OS>=20.1<20.1R1-S2, 20.1R220.1R1-S2, 20.1R2advisory ↗

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.